Numerous integrated circuits have been proposed and fabricated over the years. As devices gain faster clock speeds, a need has arisen for integrated circuits that possess the ability to function at high clock speeds with appropriate power consumption and power generation.
Some circuits, e.g. analog/digital converters, typically operate at lower frequencies as the typical method of constructing such circuits involves using printed wiring boards which can limit the functional processing speed, lower frequency integrated circuits, or a combination thereof. These circuits typically have additional cost due to the cost of housing the separate components.
Over the years, specialized devices have been developed which lend themselves to a certain class or range of operation. Pseudomorphic high electron mobility transistor (pHEMT) devices are currently used for microwave and millimeter wave integrated circuit devices (MMIC) having extremely high performance. Frequencies typically range from X-band (8 GHz) to W-band (110 GHz) for such MMIC devices.
At least three different pHEMT devices are currently fabricated: enhancement mode pHEMT, depletion mode pHEMT, and power pHEMT.